Requirements of Conjugal Love

Blueprinting for a Lasting Marriage in Christ

The Catechism of the Catholic Church defines the Sacrament of Matrimony as a “matrimonial covenant, by which a man and a woman establish between themselves a partnership of the whole of life . . . ordered toward the good of the spouses and the procreation and education of offspring.”1 This is such a loaded definition, and one which we should all look further into in order to understand how this is applicable in a life concerning conjugal love. To do so, we must look at this both from a philosophical and theological perspective. We will begin with an Aristotelian understanding of the nature of friendship and move on to the biblical and ecclesial understandings of the nature of marriage so that we can gain a fuller understanding of what constitutes a good one. For it is much easier to determine a cause for the dysfunction in a marriage by first knowing how it is supposed to function in its proper order.

The Catechism lays out the first requirement of conjugal love as the “unity and indissolubility of marriage.”2 That is, marriage must be both unifying and unbreakable. It must be unifying in the sense that both husband and wife become one and live for the good of each other, and unbreakable in the sense that nothing may come between it. Aristotle categorizes the different kinds of friendship as of: utility, pleasure, and goodness. In the case of a friendship of utility, it is not a love for each other in and of themselves, but a love of the benefit they derive from one another. Marriages commonly falling under this category could be those which people who are married for the sake of their children having both parents, or perhaps because they maintain some financial stability by being married to that person. Similarly, in friendships of pleasure, one is loved solely for the pleasure the person gets from the other.3 Marriages in this category could be due to mutual interest or because they like the way the other person makes them feel.

In a love based on pleasure, it is frequently the case that people, in their relationships, view one another as an object to reap benefits from, instead of viewing them as a subject in need of love. In doing this, one would of course be loving the person simply as a means to obtaining a particular pleasure. Aristotle distinguishes these types of love as merely accidental, as they are all concerned with loving a person incidentally, which is to be distinguished from a per se love, which is loving a person for what they are.4

Referring to the Catechism’s definition of marriage, it does not refer to either a useful or pleasurable friendship, but instead mentions being ordered toward the good of the spouses. This love Aristotle refers to as a friendship based on goodness. This, he says, is the most perfect kind of friendship because it is not temporary.5 In other words, relationships which are loved for their usefulness or pleasure will cease to be friendships once they are no longer useful or pleasant. However, a friendship based on goodness is permanent because it desires the good of the friend for the friend’s sake. This is the kind of friendship the Catechism considers as a requirement of conjugal love.

It should be noted, however, that there is nothing inherently wrong with having a relationship that is useful or pleasurable. These can be important aspects to enjoying your marriage in the fullest sense. We can have pleasurable relationships that are based on a love that is for the sake of the other. In fact, the pleasurableness could be a result of a marriage where both husband and wife are living for each other in a selfless way. Moreover, the usefulness aspect in a marriage is beneficial in that there is complementarity between the man and woman. This complementarity is “oriented towards the goods of marriage and the flourishing of family life.”6 It is perfectly natural to work in unison with each other, relying on the strengths of your spouse to complement your weaknesses so that you may become a unit that is strongest when you are together. The main point here is that a marriage cannot be based on pleasure and utility. Rather, it will display these qualities concomitantly, as a result of a mutually self-giving love.

The Scriptures bring the concept of unity and indissolubility to light by showing what really occurs in the Sacrament of Matrimony: “Therefore a man leaves his father and his mother and cleaves to his wife, and they become one flesh” (Gen 2:24). In all reality, we can now switch from looking at conjugal love as a love for the sake of ourselves. This is because, in a true conjugal love, when we do what is good for the other it should feel as if it is good for us, since what we desire most is the good of our spouse. Christ expanded on marital unity and its indissolubility by reemphasizing Genesis in saying, “So they are no longer two but one flesh. What therefore God has joined together, let not man put asunder” (Mt 19:6). We see that Scripture explicitly illustrates the unity of marriage in becoming one flesh, and the indissolubility of it by stating that in marriage a man and a woman are joined together by God, and that no man shall separate this union. The Catechism labels it as a matrimonial covenant because it is precisely that — an agreement which shall not be broken. An agreement to love the other person in a friendship based on goodness, loving each other for the sake of the other.

The second requirement of conjugal love is fidelity. This, of course, directly follows from the first requirement of unity and indissolubility, by virtue of the necessarily intimate union and unbreakable bond between the husband and wife. However, it is important to briefly juxtapose marital fidelity with the fidelity of God. Since matrimony is a covenant, we can liken it to the fidelity of Christ to his Church. Just as God loves us with a definitive and irrevocable love, we must also share in this love so “that by [our] own faithfulness [we] can be witnesses to God’s faithful love.”7 Infidelity in marriage is synonymous with an infidelity to God, and it is therefore against the nature of marriage to be unfaithful to your spouse. As St. Paul said to the Ephesians, “Husbands, love your wives, as Christ loved the church and gave himself up for her” (Eph 5:25). Fidelity is representative of a true union between a husband and wife because true unity would indicate an unbreakable oneness between them. Thus, we can see that fidelity is a consequence of a true marriage which is unifying and indissoluble.

Without fidelity in conjugal love, we are moving from a love based on goodness to a love based on pleasure. It would be essentially breaking down the foundation by which marriages are held up, one that is rightly ordered to be unifying and willfully seeking the good of the other. For example, if a spouse was to engage in sexual relations with another person, they are choosing to love pleasure more than the good of the other. Their love here would be misplaced, and contrary to its true nature as “undivided and exclusive.”8 Because infidelity disorders the way in which marriages are supposed to operate, negative consequences arise — loss of love, trust, respect, and damage to our children also follow from it. When a love is present that is truly ordered toward the good of the other there is a shift from selfishness to total self-denial. This self-denial is key to creating a lasting and sacred conjugal love. A marriage bond that receives grace from God is “intended to perfect the couple’s love and to strengthen their indissoluble unity.”9

In the Pastoral Constitution Gaudium et Spes, the term sacrifice appears three times. It is no coincidence that all three of these occurrences appear in the section concerning marriage and family. Pope Paul VI expressed the need for couples to “painstakingly cultivate and pray for steadiness of love, large-heartedness and the spirit of sacrifice”10 and to trust “in divine Providence and [refine] the spirit of sacrifice”11 so that “by the sacrifices and joys of their vocation and through their faithful love, married people can become witnesses of the mystery of love.”12 Because of our concupiscence, remaining faithful in marriage can often be a challenge, much like the challenge of remaining faithful to God and his commandments. But it is a necessary sacrifice to make, and one that will ultimately provide a true marital happiness based on a foundation of goodness and virtue.

The third and final requirement of conjugal love in the Catechism is an openness to fertility. This requirement is essential in a marriage because it is one that calls upon us to live in accordance with the laws of nature and, consequently, the will of God. We can first look at the nature of the marital (sexual) act and see that, while it does indeed unite husband and wife in the closest intimacy, it is also capable of generating new life.13 Thus, by closing off the possibility of procreation in a marriage, we would be living in a way contrary to natural law, by which we are ordered to be procreative in our nature as human beings. For us to act against our nature, we would “frustrate [God’s] design which constitutes the norm of marriage and contradicts the will of the Author of life.”14

We can find a perfect model of openness to fertility in Mary’s fiat. Scripture shows us Mary’s response to the angel Gabriel at the annunciation saying, “Behold, I am the handmaid of the Lord; let it be to me according to your word” (Lk 1:38). Here is a grand example of how we are to be open to fertility: freely cooperating with God’s plan through faith and obedience. It is a full trust in God, in knowing that he will provide, and ensuring a marriage life lived according to his will, not ours. Again, once we choose to act against our nature and the will of God, disorder is bound to follow.

Conjugal love comes further into fruition with the gift of children, and it becomes our responsibility as parents to educate our children to lead moral lives and witness for Christ by setting a good example for their children and their fellow brothers and sisters around the world. The Catechism states it is in this sense that “the fundamental task of marriage and family is to be at the service of life.”15 However, for those who have not yet had children, or cannot be granted children because of a medical condition, they can still lead a perfectly meaningful marriage. If the couple is open to the possibility of life, and continues to faithfully trust in God’s plan, “their marriage can radiate a fruitfulness of charity, of hospitality, and of sacrifice.”16

By turning to the Catechism on “The Goods and Requirements of Conjugal Love”, we are thereby able follow the blueprint for a lasting marriage. We can live out our marital life in accordance with the truths we discover by a combination of natural reason and divine revelation. Both paths to the discovery of truth, point to the necessity of the unity and indissolubility of marriage, the necessity of fidelity of conjugal love, and an openness to fertility. If these requirements are not met, the fruits of marriage will not show in their entirety, on account of a conjugal love that is disordered. Thus, these requirements should be constantly referenced as a sure guideline in living a marital life that is in line with God’s will and our nature as human beings made for one another. As God said, “It is not good that the man should be alone; I will make him a helper fit for him” (Gen 2:18).

  1. Catechism of the Catholic Church, 2nd ed. (Washington, DC: United States Catholic Conference, 2000), 1601. (Hereafter, CCC.)
  2. CCC 1644.
  3. Aristotle, The Nicomachean Ethics, trans. J.A.K. Thomson (London: Penguin Books, 2004), 204.
  4. Nicomachean Ethics, 204.
  5. Nicomachean Ethics, 205.
  6. CCC 2333.
  7. CCC 1648.
  8. CCC 1648.
  9. CCC 1641.
  10. Pope Paul VI, Pastoral Constitution on the Church in the Modern World Gaudium et Spes (December 7, 1965), no. 49. (Hereafter, GS.)
  11. GS 50.
  12. GS 52.
  13. Pope Paul VI, Encyclical on the Regulation of Birth Humanae Vitae (July 25, 1968), no. 12. (Hereafter, HV.)
  14. HV 13.
  15. CCC 2231.
  16. CCC 1654.
Paul Chutikorn About Paul Chutikorn

Paul Chutikorn lives in the Diocese of Baker and writes on various topics pertaining to the theology and philosophy of St. Thomas Aquinas. He is a husband, father of 6, and serves as Vice President of the Theological Institute of St. Thomas Aquinas (Thomisticum), as well as Director of Faith Formation at Sacred Heart Catholic Church in Klamath Falls, Oregon. He is currently pursuing his studies in both Theology and Philosophy at Holy Apostles College and Seminary.


  1. Avatar David Lassiter says:

    Thank you Paul, well written and most helpful for anyone desiring marital happiness by living the law of love within the sacrament of marriage by placing oneself at the service of love for the family. Shall we not all intone from our hearts and lips at the Wedding before the throne of God, “If I die for you, will you die for me, so that by God’s grace in our Holy Matrimony, we may live in Him now as His light in the world, and hereafter in heavenly beatitude forever!”

  2. Is it possible to address the dilemma of infertility? As a pro-life faith, its hard for some couples to hear that they do not have an absolute right to a child, esp. via AIH or AID or other methods outside of adoption or foster care.

    • Daniel A. Nicholls Daniel A. Nicholls says:

      Might I suggest that acknowledging it as a cross, and accentuating the spiritual goods of their physical relationship beside conception (e.g., through Theology of the Body), are the uncomfortable but main means to address the issue?

      Regarding the latter suggestion, here’s an HPR article on authentic intimacy, which takes as its jumping-off point a kind of neighboring case (resistance to moral teaching on sex acts within marriage) but then talks about the goods involved:

      And this, in the midst of an article more broadly on Humanae Vitae, seems a helpful point:

      “Indeed, through fidelity to the authentic expression of marital love, all marriages—whether or not physically fertile—are fruitful. A couple’s conjugal fruitfulness extends beyond conceiving a child. Obviously, those who bear offspring have the concomitant responsibility to rear their children. A married couple is called to share their love, and so they must tend to the needs of others, which may include the raising of adopted children, care of parents, or service to those in the extended family, work, parish, or community. In this way, their mutual love is sustained and strengthened. Hence, they will ask the Lord to make clear to them in what way He wants their love to be fruitful.”

      Full article: (look for a paragraph starting “In a seemingly counterintuitive and moving presentation…” about halfway in to zero in on the section about infertility).


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